Casing for transformers



Filed Feb. 9, 1924 L H BURNHAM CA5 ING FOR TRANSFORMERS feb. 17, 1925.

Inventor Locke Hfiur'rfiham,

by H i s Att orney.

Patented Feb. 17, 1925.

UNITED STATES PATENT OFFICE.

LOCKE H. BURNHAM, OF PITTS-FIELD, MASSACHUSETTS, ASSIGNOR T'O GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CASING FOR TRANSFORMERS.

Application filed February 9, 1924. Serial No. 691,793.

To all whom it may concern:

Be it known that I, LOOKE H. BURNHAM, a citizen of the United States, residing at Pittsfield, in the county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Casings for Transformers, of which the following is a specification.

My invention relates to casings for transformers and more particularly to casings adapted to contain an insulating and cooling liquid in which the transformers are immersed.

The operation of transformers results in the generation of heat in the windings and magnetic core, and this heat mustbe properly dissipated to prevent the occurrence of excessive temperatures. The dissipation of heat is commonly provided for by immersing a transformer in a suitable cooling liquid within a casing or container provided with external heat radiators. The heat generated in the transformer is absorbed by the surrounding liquid which rises by convection within the casing and thence descends through the external radiators where it is cooled to return into the casing ready to absorb more heat.

Many forms of external radiators have been used, one of the commonest forms being simple vertical tubes arranged in one or more rows around the transformer casing and communicating at their upper and lower ends with the upper and lower parts of the casing respectively. The object of the invention is to provide an improved form of tubular heat radiating element connected to a transformer casing for dissipating heat generated by a transformer immersed in a cooling liquid within the casing.

The invention will be described in connection with the accompanying drawing which shows a transformer casing equipped with heat radiating elements constructed in accordance with the invention, parts being broken away to reveal details.

As shown in the drawing, a transformer l is immersed in a cooling liquid 2 within a casing 3. The casing is provided with external heat radiating units formed in acoordance with the invention and communicating at their upper and lower ends with the upper and lower parts of the casing respectively. Heat generated in the transformer during its operation is given up to the surrounding liquid which rises by convection to the upper part of the casing, the heated liquid then descending through the heat radiating elements where it is cooled and finally returning into the lower part of the casing ready to absorb more heat from the transformer. Each heat radiating element comprises two tubes 4 and 5, the tube 4 being nearest the casing 3 and having its ends bent or turned inwardly to register with openings in the casing wall. The outer tube 5 is preferably somewhat shorter than the tube 4, and has its ends bent or turned inwardly to register with openings in the side of the inner tube 4. The joints between the tubes 4 and 5 and between the inner tubes 4t and the casing 3 are preferably welded to prevent leakage and to provide sufficient strength for the support of both tubes. The ends of the outer tube 5 communicate with the tube 4 at points which are preferably close to but between the inwardly bent ends of the inner tube at so that the outer tube 5 may be as long and present as much heat dissipating surface to the surrounding air as practicable.

After leaving the upper part of the casing 8, the heated liquid in each radiating element will separate and descend in both tubes where it is efficiently cooled by dissipation of heat from their outer surfaces. WVith the construction described, the outer tubes 5 do not interfere with or obstruct the free upward flow of cooling air between the inner tubes 4: and the casing wall and the effectiveness of the outer tubes 5 is obtained without the necessity of forming additional openings for them in the casing wall.

lVhat I claim as new and desire to secure by Letters Patent of the United States is 1. The combination with a casing for a transformer immersed in acooling liquid, of external heat radiating elements, each of said elements comprising an inner tube having its ends turned inwardly to said casing and communicating therewith, and an outer tube having its ends turned inwardly to said inner tube and communicatine therewith.

2. The combination with a casing for a transformer immersed in a cooling liquid, of external heat radiating elements, each of said elements comprising an inner tube having itsends turned inwardly to said casing and communicating therewith, and an outer tube having its ends turned inwardly to 10 said inner tube and communicating therewith at points between the inward- "iy turned ends of said inner tube.

In witness whereof, I have hereunto set my hand this 5th day of February 1924.

LOGKE H. BURNHAM. 

